Roy Keane has launched a withering attack on Manchester United, saying that the club's vice-chairman, Ed Woodward, "needs to look at himself" over the failure to secure quality signings last summer and that players such as Phil Jones must toughen up.

While the former United captain believes that Louis van Gaal would be a good appointment, he said that David Moyes deserved more time. Keane insisted that Moyes, who was sacked after 10 months in charge, should not be held accountable for the way that United missed out on a number of their main targets last summer and that Woodward has to get deals done if there is to be improvement next season.

"He [Moyes] had one transfer window, and it's not always down to the manager when players don't come in," said Keane, who was speaking at ITV's World Cup launch. "I think Ed Woodward needs to look at himself. He's got to get deals done. I think he should have been given more time. I was happy with David Moyes. I think Van Gaal is a good choice. Only time will tell. He's managed big clubs."

Keane believes that Jones and Chris Smalling have both gone backwards over the past year. "They've had a platform for the last couple of years," he said. "We were told two or three years ago Jones was going to be the new Duncan Edwards, Smalling was this … I've watched United live nine, 10 times this year and they have been none of those things. If anything I think they have gone backwards. I've actually been a big fan of them – yes, give them a chance, you say you have to give players a chance to mature but also you've got players who you say we've given you a chance and you're not taking it.

"They need to do a lot better if they want to cement their place at Man United and United to win trophies. Jones needs to toughen up. Every time I see him he is getting carried off. He's got to toughen up – he's playing for Man United. They have to recruit in the summer – they might get two.

"It's the spine of the team. United have come up short defensively and in the middle of the park they have not done enough. You watch any of the teams that are winning trophies, Jesus I'm stating the obvious, you've got to have a strong spine, goalkeeper, defender, midfielder and striker and United have been short in two of those areas. It makes it very difficult to win trophies."

Keane was not surprised that Rio Ferdinand will leave United this summer or bothered that the defender was not given a chance to say goodbye to the Old Trafford crowd.

"That might have suited him," he said. "Not everybody wants to wander around the pitch waving and crying. It's not about walking on the pitch – I don't know where you're going with this one. He didn't have a chance to say goodbye? You can say goodbye on Twitter, can't you?"